Technical Abstract: Four species of insect-killing nematodes were exposed to freezing temperatures while inside their hosts. Survival was assessed by observing live and dead nematodes inside cadavers and by counting the infective juveniles (IJs) tht emerged after freezing. We 1) measured the effects of 24 hours of freezing at different times throughout the course of an infection, 2) determined the duration of freezing entomopathogenic nematodes could survive, 3) determined species differences in freezing survival. For S. carpocapsae and H. bacteriophora, the stages that survived were predominately IJs and adults. When cadavers were frozen two or three days after infection, few IJs emerged from them. Freezing between five and seven days after infection usually had no negative effect on IJ production. Heterorhabditis bacteriophora produced the most IJs after freezing. Heterorhabditis bacteriophora also showed improved survival inside versus outside their host when exposed to freezing.